1. Field
At lest one example embodiment relates to optical elements and information storage devices including the same.
2. Description of the Related Art
In the field of information storage devices such as magnetic recording devices, research has been continuously conducted to increase recording density. The thermal stability of data recorded on a magnetic recording medium is proportional to a ratio between magnetic anisotropic energy and thermal energy, i.e., KUV/kBT. Here, KU represents a magnetic anisotropic energy density of a magnetic recording medium, V represents a volume of a magnetic grain, kB represents a Boltzmann constant, and T represents an absolute temperature. In order to increase the thermal stability of data, a material having a high magnetic anisotropic energy density KU should be used to form a recording medium. However, if a material having a high magnetic anisotropic energy density KU is used, the intensity of a magnetic field required to record data is increased.
According to heat assisted magnetic recording (HAMR), a local portion of a recording medium is heated to temporarily reduce a coercive force of the local portion, and then data is recorded on the heated portion of the recording medium. By heating, the intensity of a magnetic field used to record data may be reduced.